xref: /openbmc/u-boot/drivers/serial/ns16550.c (revision 48f8e159)
1 /*
2  * COM1 NS16550 support
3  * originally from linux source (arch/powerpc/boot/ns16550.c)
4  * modified to use CONFIG_SYS_ISA_MEM and new defines
5  */
6 
7 #include <common.h>
8 #include <clk.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <ns16550.h>
12 #include <reset.h>
13 #include <serial.h>
14 #include <watchdog.h>
15 #include <linux/types.h>
16 #include <asm/io.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
21 #define UART_MCRVAL (UART_MCR_DTR | \
22 		     UART_MCR_RTS)		/* RTS/DTR */
23 
24 #ifndef CONFIG_DM_SERIAL
25 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
26 #define serial_out(x, y)	outb(x, (ulong)y)
27 #define serial_in(y)		inb((ulong)y)
28 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
29 #define serial_out(x, y)	out_be32(y, x)
30 #define serial_in(y)		in_be32(y)
31 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
32 #define serial_out(x, y)	out_le32(y, x)
33 #define serial_in(y)		in_le32(y)
34 #else
35 #define serial_out(x, y)	writeb(x, y)
36 #define serial_in(y)		readb(y)
37 #endif
38 #endif /* !CONFIG_DM_SERIAL */
39 
40 #if defined(CONFIG_SOC_KEYSTONE)
41 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
42 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
43 #undef UART_MCRVAL
44 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
45 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
46 #else
47 #define UART_MCRVAL             (UART_MCR_RTS)
48 #endif
49 #endif
50 
51 #ifndef CONFIG_SYS_NS16550_IER
52 #define CONFIG_SYS_NS16550_IER  0x00
53 #endif /* CONFIG_SYS_NS16550_IER */
54 
55 static inline void serial_out_shift(void *addr, int shift, int value)
56 {
57 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
58 	outb(value, (ulong)addr);
59 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
60 	out_le32(addr, value);
61 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
62 	out_be32(addr, value);
63 #elif defined(CONFIG_SYS_NS16550_MEM32)
64 	writel(value, addr);
65 #elif defined(CONFIG_SYS_BIG_ENDIAN)
66 	writeb(value, addr + (1 << shift) - 1);
67 #else
68 	writeb(value, addr);
69 #endif
70 }
71 
72 static inline int serial_in_shift(void *addr, int shift)
73 {
74 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
75 	return inb((ulong)addr);
76 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
77 	return in_le32(addr);
78 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
79 	return in_be32(addr);
80 #elif defined(CONFIG_SYS_NS16550_MEM32)
81 	return readl(addr);
82 #elif defined(CONFIG_SYS_BIG_ENDIAN)
83 	return readb(addr + (1 << shift) - 1);
84 #else
85 	return readb(addr);
86 #endif
87 }
88 
89 #ifdef CONFIG_DM_SERIAL
90 
91 #ifndef CONFIG_SYS_NS16550_CLK
92 #define CONFIG_SYS_NS16550_CLK  0
93 #endif
94 
95 static void ns16550_writeb(NS16550_t port, int offset, int value)
96 {
97 	struct ns16550_platdata *plat = port->plat;
98 	unsigned char *addr;
99 
100 	offset *= 1 << plat->reg_shift;
101 	addr = (unsigned char *)plat->base + offset;
102 
103 	/*
104 	 * As far as we know it doesn't make sense to support selection of
105 	 * these options at run-time, so use the existing CONFIG options.
106 	 */
107 	serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
108 }
109 
110 static int ns16550_readb(NS16550_t port, int offset)
111 {
112 	struct ns16550_platdata *plat = port->plat;
113 	unsigned char *addr;
114 
115 	offset *= 1 << plat->reg_shift;
116 	addr = (unsigned char *)plat->base + offset;
117 
118 	return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
119 }
120 
121 static u32 ns16550_getfcr(NS16550_t port)
122 {
123 	struct ns16550_platdata *plat = port->plat;
124 
125 	return plat->fcr;
126 }
127 
128 /* We can clean these up once everything is moved to driver model */
129 #define serial_out(value, addr)	\
130 	ns16550_writeb(com_port, \
131 		(unsigned char *)addr - (unsigned char *)com_port, value)
132 #define serial_in(addr) \
133 	ns16550_readb(com_port, \
134 		(unsigned char *)addr - (unsigned char *)com_port)
135 #else
136 static u32 ns16550_getfcr(NS16550_t port)
137 {
138 	return UART_FCR_DEFVAL;
139 }
140 #endif
141 
142 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
143 {
144 	const unsigned int mode_x_div = 16;
145 
146 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
147 }
148 
149 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
150 {
151 	/* to keep serial format, read lcr before writing BKSE */
152 	int lcr_val = serial_in(&com_port->lcr) & ~UART_LCR_BKSE;
153 
154 	serial_out(UART_LCR_BKSE | lcr_val, &com_port->lcr);
155 	serial_out(baud_divisor & 0xff, &com_port->dll);
156 	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
157 	serial_out(lcr_val, &com_port->lcr);
158 }
159 
160 void NS16550_init(NS16550_t com_port, int baud_divisor)
161 {
162 #if (defined(CONFIG_SPL_BUILD) && \
163 		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
164 	/*
165 	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
166 	 * before SPL starts only THRE bit is set. We have to empty the
167 	 * transmitter before initialization starts.
168 	 */
169 	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
170 	     == UART_LSR_THRE) {
171 		if (baud_divisor != -1)
172 			NS16550_setbrg(com_port, baud_divisor);
173 		serial_out(0, &com_port->mdr1);
174 	}
175 #endif
176 
177 	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
178 		;
179 
180 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
181 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_OMAP_SERIAL)
182 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
183 #endif
184 
185 	serial_out(UART_MCRVAL, &com_port->mcr);
186 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
187 	/* initialize serial config to 8N1 before writing baudrate */
188 	serial_out(UART_LCRVAL, &com_port->lcr);
189 	if (baud_divisor != -1)
190 		NS16550_setbrg(com_port, baud_divisor);
191 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_SOC_DA8XX) || \
192 	defined(CONFIG_OMAP_SERIAL)
193 	/* /16 is proper to hit 115200 with 48MHz */
194 	serial_out(0, &com_port->mdr1);
195 #endif
196 #if defined(CONFIG_SOC_KEYSTONE)
197 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
198 #endif
199 }
200 
201 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
202 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
203 {
204 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
205 	NS16550_setbrg(com_port, 0);
206 	serial_out(UART_MCRVAL, &com_port->mcr);
207 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
208 	NS16550_setbrg(com_port, baud_divisor);
209 }
210 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
211 
212 void NS16550_putc(NS16550_t com_port, char c)
213 {
214 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
215 		;
216 	serial_out(c, &com_port->thr);
217 
218 	/*
219 	 * Call watchdog_reset() upon newline. This is done here in putc
220 	 * since the environment code uses a single puts() to print the complete
221 	 * environment upon "printenv". So we can't put this watchdog call
222 	 * in puts().
223 	 */
224 	if (c == '\n')
225 		WATCHDOG_RESET();
226 }
227 
228 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
229 char NS16550_getc(NS16550_t com_port)
230 {
231 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
232 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
233 		extern void usbtty_poll(void);
234 		usbtty_poll();
235 #endif
236 		WATCHDOG_RESET();
237 	}
238 	return serial_in(&com_port->rbr);
239 }
240 
241 int NS16550_tstc(NS16550_t com_port)
242 {
243 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
244 }
245 
246 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
247 
248 #ifdef CONFIG_DEBUG_UART_NS16550
249 
250 #include <debug_uart.h>
251 
252 static inline void _debug_uart_init(void)
253 {
254 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
255 	int baud_divisor;
256 
257 	/*
258 	 * We copy the code from above because it is already horribly messy.
259 	 * Trying to refactor to nicely remove the duplication doesn't seem
260 	 * feasible. The better fix is to move all users of this driver to
261 	 * driver model.
262 	 */
263 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
264 					    CONFIG_BAUDRATE);
265 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
266 	serial_dout(&com_port->mcr, UART_MCRVAL);
267 	serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
268 
269 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
270 	serial_dout(&com_port->dll, baud_divisor & 0xff);
271 	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
272 	serial_dout(&com_port->lcr, UART_LCRVAL);
273 }
274 
275 static inline int NS16550_read_baud_divisor(struct NS16550 *com_port)
276 {
277 	int ret;
278 
279 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
280 	ret = serial_din(&com_port->dll) & 0xff;
281 	ret |= (serial_din(&com_port->dlm) & 0xff) << 8;
282 	serial_dout(&com_port->lcr, UART_LCRVAL);
283 
284 	return ret;
285 }
286 
287 static inline void _debug_uart_putc(int ch)
288 {
289 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
290 
291 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE)) {
292 		if (!NS16550_read_baud_divisor(com_port))
293 			return;
294 	}
295 	serial_dout(&com_port->thr, ch);
296 }
297 
298 DEBUG_UART_FUNCS
299 
300 #endif
301 
302 #ifdef CONFIG_DM_SERIAL
303 static int ns16550_serial_putc(struct udevice *dev, const char ch)
304 {
305 	struct NS16550 *const com_port = dev_get_priv(dev);
306 
307 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
308 		return -EAGAIN;
309 	serial_out(ch, &com_port->thr);
310 
311 	/*
312 	 * Call watchdog_reset() upon newline. This is done here in putc
313 	 * since the environment code uses a single puts() to print the complete
314 	 * environment upon "printenv". So we can't put this watchdog call
315 	 * in puts().
316 	 */
317 	if (ch == '\n')
318 		WATCHDOG_RESET();
319 
320 	return 0;
321 }
322 
323 static int ns16550_serial_pending(struct udevice *dev, bool input)
324 {
325 	struct NS16550 *const com_port = dev_get_priv(dev);
326 
327 	if (input)
328 		return (serial_in(&com_port->lsr) & UART_LSR_DR) ? 1 : 0;
329 	else
330 		return (serial_in(&com_port->lsr) & UART_LSR_THRE) ? 0 : 1;
331 }
332 
333 static int ns16550_serial_getc(struct udevice *dev)
334 {
335 	struct NS16550 *const com_port = dev_get_priv(dev);
336 
337 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
338 		return -EAGAIN;
339 
340 	return serial_in(&com_port->rbr);
341 }
342 
343 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
344 {
345 	struct NS16550 *const com_port = dev_get_priv(dev);
346 	struct ns16550_platdata *plat = com_port->plat;
347 	int clock_divisor;
348 
349 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
350 
351 	NS16550_setbrg(com_port, clock_divisor);
352 
353 	return 0;
354 }
355 
356 static int ns16550_serial_setconfig(struct udevice *dev, uint serial_config)
357 {
358 	struct NS16550 *const com_port = dev_get_priv(dev);
359 	int lcr_val = UART_LCR_WLS_8;
360 	uint parity = SERIAL_GET_PARITY(serial_config);
361 	uint bits = SERIAL_GET_BITS(serial_config);
362 	uint stop = SERIAL_GET_STOP(serial_config);
363 
364 	/*
365 	 * only parity config is implemented, check if other serial settings
366 	 * are the default one.
367 	 */
368 	if (bits != SERIAL_8_BITS || stop != SERIAL_ONE_STOP)
369 		return -ENOTSUPP; /* not supported in driver*/
370 
371 	switch (parity) {
372 	case SERIAL_PAR_NONE:
373 		/* no bits to add */
374 		break;
375 	case SERIAL_PAR_ODD:
376 		lcr_val |= UART_LCR_PEN;
377 		break;
378 	case SERIAL_PAR_EVEN:
379 		lcr_val |= UART_LCR_PEN | UART_LCR_EPS;
380 		break;
381 	default:
382 		return -ENOTSUPP; /* not supported in driver*/
383 	}
384 
385 	serial_out(lcr_val, &com_port->lcr);
386 	return 0;
387 }
388 
389 int ns16550_serial_probe(struct udevice *dev)
390 {
391 	struct NS16550 *const com_port = dev_get_priv(dev);
392 	struct reset_ctl_bulk reset_bulk;
393 	int ret;
394 
395 	ret = reset_get_bulk(dev, &reset_bulk);
396 	if (!ret)
397 		reset_deassert_bulk(&reset_bulk);
398 
399 	com_port->plat = dev_get_platdata(dev);
400 	NS16550_init(com_port, -1);
401 
402 	return 0;
403 }
404 
405 #if CONFIG_IS_ENABLED(OF_CONTROL)
406 enum {
407 	PORT_NS16550 = 0,
408 	PORT_JZ4780,
409 };
410 #endif
411 
412 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
413 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
414 {
415 	struct ns16550_platdata *plat = dev->platdata;
416 	const u32 port_type = dev_get_driver_data(dev);
417 	fdt_addr_t addr;
418 	struct clk clk;
419 	int err;
420 
421 	/* try Processor Local Bus device first */
422 	addr = dev_read_addr(dev);
423 #if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
424 	if (addr == FDT_ADDR_T_NONE) {
425 		/* then try pci device */
426 		struct fdt_pci_addr pci_addr;
427 		u32 bar;
428 		int ret;
429 
430 		/* we prefer to use a memory-mapped register */
431 		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev_of_offset(dev),
432 					  FDT_PCI_SPACE_MEM32, "reg",
433 					  &pci_addr);
434 		if (ret) {
435 			/* try if there is any i/o-mapped register */
436 			ret = fdtdec_get_pci_addr(gd->fdt_blob,
437 						  dev_of_offset(dev),
438 						  FDT_PCI_SPACE_IO,
439 						  "reg", &pci_addr);
440 			if (ret)
441 				return ret;
442 		}
443 
444 		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
445 		if (ret)
446 			return ret;
447 
448 		addr = bar;
449 	}
450 #endif
451 
452 	if (addr == FDT_ADDR_T_NONE)
453 		return -EINVAL;
454 
455 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
456 	plat->base = addr;
457 #else
458 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
459 #endif
460 
461 	plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
462 	plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
463 
464 	err = clk_get_by_index(dev, 0, &clk);
465 	if (!err) {
466 		err = clk_get_rate(&clk);
467 		if (!IS_ERR_VALUE(err))
468 			plat->clock = err;
469 	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
470 		debug("ns16550 failed to get clock\n");
471 		return err;
472 	}
473 
474 	if (!plat->clock)
475 		plat->clock = dev_read_u32_default(dev, "clock-frequency",
476 						   CONFIG_SYS_NS16550_CLK);
477 	if (!plat->clock) {
478 		debug("ns16550 clock not defined\n");
479 		return -EINVAL;
480 	}
481 
482 	plat->fcr = UART_FCR_DEFVAL;
483 	if (port_type == PORT_JZ4780)
484 		plat->fcr |= UART_FCR_UME;
485 
486 	return 0;
487 }
488 #endif
489 
490 const struct dm_serial_ops ns16550_serial_ops = {
491 	.putc = ns16550_serial_putc,
492 	.pending = ns16550_serial_pending,
493 	.getc = ns16550_serial_getc,
494 	.setbrg = ns16550_serial_setbrg,
495 	.setconfig = ns16550_serial_setconfig
496 };
497 
498 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
499 /*
500  * Please consider existing compatible strings before adding a new
501  * one to keep this table compact. Or you may add a generic "ns16550"
502  * compatible string to your dts.
503  */
504 static const struct udevice_id ns16550_serial_ids[] = {
505 	{ .compatible = "ns16550",		.data = PORT_NS16550 },
506 	{ .compatible = "ns16550a",		.data = PORT_NS16550 },
507 	{ .compatible = "ingenic,jz4780-uart",	.data = PORT_JZ4780  },
508 	{ .compatible = "nvidia,tegra20-uart",	.data = PORT_NS16550 },
509 	{ .compatible = "snps,dw-apb-uart",	.data = PORT_NS16550 },
510 	{}
511 };
512 #endif /* OF_CONTROL && !OF_PLATDATA */
513 
514 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
515 
516 /* TODO(sjg@chromium.org): Integrate this into a macro like CONFIG_IS_ENABLED */
517 #if !defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL)
518 U_BOOT_DRIVER(ns16550_serial) = {
519 	.name	= "ns16550_serial",
520 	.id	= UCLASS_SERIAL,
521 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
522 	.of_match = ns16550_serial_ids,
523 	.ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
524 	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
525 #endif
526 	.priv_auto_alloc_size = sizeof(struct NS16550),
527 	.probe = ns16550_serial_probe,
528 	.ops	= &ns16550_serial_ops,
529 #if !CONFIG_IS_ENABLED(OF_CONTROL)
530 	.flags	= DM_FLAG_PRE_RELOC,
531 #endif
532 };
533 #endif
534 #endif /* SERIAL_PRESENT */
535 
536 #endif /* CONFIG_DM_SERIAL */
537